Do we have any news about this?
Just picked up Playfab again for our next game and my collegues in office with Windows experience the same problem. I have verified with my Windows computer from home and getting the same error. MacOSX works just fine.
WARNING:DLIB: Unhandled ssl status code: -261
ERROR:SCRIPT: HTTP request to 'https://****.playfabapi.com//Client/LoginWithCustomID' failed (http result: -1 socket result: -1000)